Cardiac arrest (CA) is one of the main causes of death in the western world. After the heart has stopped pumping, death is unavoidable unless acute medical care is available. The resulting ischemia disturbs a wide range of cell processes; this eventually leads to cell death. It has been reported that the probability for survival after cardiac arrest decreases exponentially with time. To slow down this decay, Cardio Pulmonary Resuscitation (CPR) has to be performed to obtain a minimum amount of perfusion to vital organs. Cardio Pulmonary Resuscitation (CPR) guidelines prescribe a standard compression depth and frequency (i.e. 100 compressions per minute at a depth of 5.0 cm). This prescribed depth and frequency are person independent. However, the compression depth and frequency that generate optimal blood flows vary between people. To optimally resuscitate a patient, the quality of CPR has to be assessed in some way. In the experimental setting this can be done by measuring blood flows (e.g. carotid or aortic flow) or coronary perfusion pressure (CPP).The CPP measures the pressure drop over the coronary vessels of the heart (Aortic pressure—Right Atrial pressure). However these values require precise and timely placement of measurement catheters, which is not practical during normal clinical practice. In clinical practice, some non- or minimally invasive techniques are being used as surrogate marker of CPR quality. The highest point of expired carbon dioxide trace (End tidal CO2, ETCO2) of a breath is believed to give some information on the quality of CPR. ETCO2 is shown to rise when the heart starts beating on its own (Return of Spontaneous Circulation, ROSC). While giving some indication of the CPR quality, the ETCO2 is influenced by changes in ventilation minute volume (i.e. ventilation frequency and volume), ventilation/perfusion ratio and medication. Further, it takes a significant amount of time (tens of seconds) for ETCO2 to reach a new steady state. Giving feedback on this parameter is therefore not an easy task. No quantitative feedback algorithms/methods exist yet for using this parameter. In this disclosure it is proposed to use certain features of the blood pressure as quality of CPR indicator.
There are a number of devices that measure CPR quality in term of guideline adherence, i.e. giving the prescribed compression depth and frequency. These feedback devices are however not suitable for personalization of CPR.
A system for providing feedback on chest compression in CPR is for example described in EP 1 932 502. The system measures and processes chest compressions and provide feedback to the user with respect to the characteristics of the compressions.
An apparatus for indicating cardiac output comprises means for monitoring a patient's transthoracic impedance and generating a corresponding impedance signal is described in WO2009/109595.
US 2012/259156 A1 describes a device for coordinated resuscitation perfusion support. A system capable of providing electromagnetic stimulation of physiological tissue to supplement the effect of manual CPR is described. Use of different physiological input signals and different compression parameters are proposed.
US 2007/060785 A1 describes a medical device for assisting a user in manually delivering e.g. CPR. In an embodiment, an ultrasonic sensor for blood flow is mentioned in combination with CPR, wherein an estimated blood flow is used to determine timing of feedback cues delivered to a user.
The inventor of the present invention has appreciated that an improved system, apparatus and method is of benefit, and has in consequence devised the present invention.